A thick layer of thatch does one thing for your lawn, and that is to create unhealthy growing conditions that foster the growth of fungi and pests that cause diseases that damage the lawn and ultimately result in the premature death of turfgrass.

Removing thatch buildup also known as “Dethatching”, allows air, water, and nutrients to reach the soil which can be blocked by a thick layer of thatch. By bolstering these three vital elements, your lawn will grow in thicker, healthier, and greener.

Dethatching is a lawn management technique that is a necessary part of maintaining a healthy lawn. It improves the soil fertilizer intake, which, when absorbed into the soil, enhances the growth of a lush and beautiful lawn.

Why dethatch my lawn?

What does Dethatching do for Your Lawn

Removing excess thatch is beneficial to your lawn because a thick layer of thatch limits the effectiveness of lawn treatments and techniques, leaving you with a weakened lawn that is susceptible to drought, diseases, and pest infestation.

There are so many reasons to dethatch your lawn. Lawn keepers dethatch regularly to ensure a healthy and vigorously growing grass. Other reasons to dethatch include:

  1. To allow turfgrass to establish deeper roots, thus, increasing the drought resistance of the lawn.
  2. To encourage the deeper movement of air, water, and fertilizer into the root zone to stimulate root growth
  3. Dethatching opens up the surface of your lawn, exposing the soil to sunlight and warmth after a cold winter.
  4. To establish a greener and uniform growing lawn.
  5. Dethatching increases your lawn water absorption rate. It allows water to penetrate deeper into the ground reducing pudding.
  6. To increase the lawn’s intake of the fertilizers, herbicides, and pesticides formerly trapped within the thatch layer.

Is dethatching necessary?

Knowing when to dethatch a lawn is important because not all lawns with thatch need dethatching. A tool to see if it’s necessary to dethatch is by walking across your lawn. A yard with excessive thatch will have a spongy or bouncy feel. If you notice this, it may be time to dethatch.

Although a thin layer of thatch insulates the soil against high temperatures, among other benefits, thatch becomes a problem when the thickness exceeds ½ inch. Most lawn keepers make the mistake of dethatching without checking the thickness of the thatch layer. In the process, many lawns have had the beneficial layer of thatch removed, resulting in all kinds of lawn problems. The number one rule is to check your lawn thatch thickness before dethatching.

Get on your knees for a closer inspection, cut and remove a wedge of your lawn to examine its profile. Thatch generally appears as an unmistakable layer of threadlike material wedged in-between the soil surface and grass stems. Use a ruler to measure the thickness of the thatch layer. Oklahoma State University Department of Agricultural Sciences says cool-season grass lawns shouldn’t have a thatch layer exceeding ⅓ inches, and you should dethatch if it measures between ⅓ – 1 inches. For warm-season grass lawns, the perfect thatch layer should be less than ½ inches. However, if the thatch layer exceeds ½ inch, then it is necessary to dethatch your lawn.

How often should I dethatch my lawn?

You can dethatch your lawn once a year to keep thatch at bay. But since thatch usually builds up over time, how often you detach will depend on the lawn type and soil conditions.

Cold season grass lawns are widely known to produce the least amounts of thatch, and you can dethatch every couple of years during fall or spring seasons. Warm-season grass lawns, however, generate thatch at faster rates, and you must dethatch annually during late fall or summer.

Lawns with acidic, wet, and soggy soils produce thatch faster than it is being broken down, and they’ll need dethatching more often than lawns with loamy or sandy/loam soils. Test your lawn soil to determine if it hinders microbial activities that are responsible for breaking thatch. If the soil type falls in that category, then you’ll need to dethatch your lawn more frequently.

What’s the next steps after dethatching?

After dethatching your lawn, it might be an excellent time to aerate and overseed to recover the grass lost to dethatching. Professionals also recommend fertilizing your lawn after dethatching to restore the color and thickness of your lawn grass. In this section, we will examine each of the three post-dethatching procedures and their benefits.

Aerating

Aerating should be done immediately after dethatching your lawn to encourage the movement of oxygen, water, and nutrients into the soil. Aeration is exceptionally crucial if your goal is to overseed your lawn after dethatching because it loosens the soil to allow fertilizer and nutrients trapped by the thatch layer to penetrate the ground. The holes left after aeration provide nurturing spaces for grass seedlings to receive access to the elements essential for their germination.

Overseeding

Dethatching can leave unsightly patches and bare sections on your lawn. Overseeding is a terrific seeding technique that offers lawn keepers a practical and straightforward alternative for regrowing their lawn. A significant benefit of overseeing is that you can grow new grass varieties without getting rid of the existing lawn. Also, overseeding helps to ‘fill-in’ the barren patches and regrow lost sections of grass. Overseed during the fall season to benefit from the best growing conditions due to lower temperatures and higher soil moisture levels, which helps seedlings germinate faster and grow deeper and stronger roots necessary to create a healthy lawn.

Fertilizing

Fertilizing after dethatching helps the soil get more nutrients, and it nurtures the weakened and stressed lawn grass. Also, newly seeded grass seedlings benefit from fertilization. However, lawn keepers must fertilize sparingly to prevent an overabundance of thatch.

When is the best time of year to dethatch?

Dethatching your grass is worth it, especially during your lawn grass’s active growth periods to speed up turf recovery and regrowth. These periods should fall between spring and early fall, depending on your lawn grass type. Cool-season grass grows faster during the cool conditions of late summer and early fall, which is the best time to dethatch lawns with fescue, bluegrass, and ryegrass. Dethatch lawns with warm-season grass such as Bermuda and buffalo grass during their late spring through early summer active growing period after being mowed a couple of times. Lawns with Zoysia Grass should be dethatched during summer.

Should I mow before dethatching?

Mowing before dethatching decreases the chances of pulling healthy grasses out of your lawn during dethatching. Lawn experts recommend mowing your lawn to less than half its standard height before you commence detaching.

FAQ's

There are several ways of getting rid of thatch naturally without using invasive dethatching methods that stress your grass and damage your lawn. These include growing cool-season grasses that produce lesser quantities of thatch than warm-season grass varieties. Also, encouraging the spread of earthworms on your lawn and leaving lawn clippings are effective natural methods of ridding your yard of thatch because they promote the growth of microbial agents that break down the thatch layer.

Dethatching cost per square foot range from $10 – $20. Lawns with particularly severe thatch build-up can cost as high as $40 per square foot to dethatch. The average cost to dethatch a 5,000 square foot lawn is around $540, including debris removal and other cleaning up activities.

Dethatching is an invasive thatch management technique that has the potential to damage your lawn if not performed correctly. Dethatching machines have sharp metal blades or times that operate by ripping thatch out of your lawn – along with substantial amounts of healthy grass. You can limit the damage to your lawn by hiring a skilled and experienced professional to dethatch your lawn, adjusting the blades of dethatching equipment to suit your lawn grass height also minimizes damage to your lawn.

Benjamin McInerny
Author: Benjamin McInerny - is a qualified arborist and a DIY Home Improvement enthusiast. Ben has a extensive experience on renovation projects including, mold removal, painting, fence installation and more. Ben shares his skills with DIY and gardening enthusiasts.